Publication and Communication

Structural confirmation of the sea ice biomarker IP25 found in Arctic marine sediments

University of Plymouth, Division Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences

Journal Name

Environmental Chemistry Letters

Abstract

IP25 is a highly branched isoprenoid and an organic geochemical biomarker that is produced by some Arcticsea ice diatoms. IP25 has previously been used in Arctic palaeo sea ice reconstruction studies and as a tracer for studying Arctic food webs. Here, the molecular structure of IP25 has been confirmed by 1H and 13C NMR spectroscopy following large-scale extraction from marine sediments obtained from the Canadian Arctic andpurification using a combination of open-column and HPLC chromatographic methods. The structure ofIP25 was consistent between the three different sampling locations and was identical to that found previouslyfor this biomarker following synthesis from a closely related highly branched isoprenoid diene. Since thisstudy represents the first structural characterisation of IP25 in sediments, future analysis of sedimentary IP25for palaeo Arctic sea ice reconstructions can be carried out with much greater confidence.